Long-Term Agricultural Effects on the Authentication Accuracy of Organic, Green, and Conventional Rice Using Isotopic and Elemental Chemometric Analyses.

Organically farmed rice is believed to be healthier, safer and eco-friendlier than its conventionally farmed counter-part and sells for a premium price in global markets. Deliberate mislabeling of organic rice has become a critical consumer concern in China and elsewhere, and there is increased risk of buying fraudulent organic rice in the market place. In this study, stable isotope and multi-element analysis combined with chemometrics was used to differentiate organically farmed rice from green and conventional rice in a four-year experimental field trial from 2014 to 2017. A total of 108 rice samples and their associated soils were collected during the study from three farming (fertilization) systems to investigate if there are long-term changes in the rice farming classification accura-cy from climate effects. Stable carbon, nitrogen isotope ratios (i.e. δ13C and δ15N) and 27 elemental contents (e.g. Na, K, Ca, Fe, Zn) of rice and soil samples were determined, then evaluated using statistical analysis ...